At present in United States tires to be disposed of in a landfill must be cut into a minimum of four segments. There is then a need for a tire cutting tool that will cut both large and small tires in a rapid and economical manner in four or more segments.
The subject invention is aimed at filling this need for a versatile economical tire cutting tool. Since there are many small shops handling used tires a cutting tool that is rugged, fast acting and portable is desirable. We accomplish this by mounting a hydraulic drive cylinder with about 31/2" diameter to drive a curved single blade cutter to cuttably engage a tire between the cutter and an open faced anvil mounted vertically on about a 6" steel beam. A drive motor that may be electrical or gasoline driven and an oil pump capable of pumping oil to operate the hydraulic cylinder at up to 3,000 psi is also mounted on the steel beam.
In a preferred embodiment, one end of the beam is mounted between wheels in a manner similar to a normal two wheel trailer. The other end of the beam is equipped to connect with a trailer hitch on a vehicle.
The curved single blade cutter is pivotally connected at the base and between the two faces of the anvil, or cutter back up plates, adjacent to the mounting beam. The anvil may be about three foot tall and is mounted vertically at right angles to the steel beam or mounting frame. Metal braces are welded between the back portion of the anvil and the mounting beam. The cutter shape is essentially as shown in drawings herein and is connected with the hydraulic drive cylinder so that as the extensible drive rod retracts the cutter there will be ample space to allow a tire to be moved between the curved end of the cutter and the faces of the cutter anvil. In a preferred embodiment, rollers on each side of the cutter are positioned so that when the cutter is in a fully retracted position that the edge of the cutting face of the cutter is below the rollers allowing a tire to be moved into a cutting position on the rollers.
A 6 h.p. motor is used to drive the oil pump supplying the oil to activate the hydraulic drive cylinder. With the large drive motor and oil pump that will supply oil at 3,000 psi to the hydraulic cylinder the cutter may be moved rapidly.
After a tire is in the cutting position, the equipment operator manually operates a lever to operate a two valve to cause the hydraulic drive cylinder to either retract or to extend the extensible drive rod to force the drive blade through the tire. With equipment as described there is approximately 10,000 pounds of force available to activate the cutter blade but in practice approximately 1,200 psi on oil to the hydraulic cylinder cuts even the larger tires quite easily. It is important that the tips of the cutter blade enters between the faces of the anvil first as the cutter blades starts to compress the tire and thereby holds the tire in a cuttable position and holds the blade in one plane as pressure increases to cut the tire.
The equipment is designed to allow the operator to rapidly extend or retract the cutter blade by simple movement of a lever.
There are several machines or tools for cutting a tire in the prior art. All differ significantly from our invention.
We would consider U.S. Pat. No. 4,805,507 to be pertinent. In U.S. Pat. No. 4,805,507 to Schmidt et al, a tire cutting machine is described wherein a vertical blade is driven by a hydraulic ram into a dual faced vertical anvil. A cutter with a scalloped edge is used to aid in preventing the tire from riding up on the shear. In our invention we use a curved cutter blade to hold the tire in position as the cutter engages the tire and most importantly the curved tip enters an anvil with a single adjustable cutter face before the pressure to actually cut the tire is applied. The guidance by the cutter tip is necessary to hold a cutter blade closely enough in one plane and allows use of a thin sharpened blade to allow rapid cutting of tires with a simple machine. One operator with our machine may cut 150 tires in an hour.